Diogu stands at 6 foot 9 inches (2.06 m) tall which is considered slightly undersized for an NBA power forward, but he makes up for his lack of height with his muscle, girth and 7'4" wingspan.[2]

Diogu attended Arizona State University, where he excelled on the team under head coach Rob Evans. He garnered several honors, both in the Pac-10 Conference and nationally. He won Pac-10 Freshman of the Year, and then Pac-10 Player of the Year in his final season with ASU, as a Junior. Many in the public speculated that Diogu would enter the draft after playing for his third season with Arizona State. On June 21, 2005, he made the decision to enter the NBA draft.

Diogu was selected 9th overall in the first round of the 2005 NBA Draft by the Golden State Warriors. On December 23, 2005, he recorded a professional career-best 27 points on 13–15 shooting, surpassing his previous best by 12 points.[3]